Field of the Invention
The present invention relates to an electrophotographic photoreceptor for forming electrophotographic images, an image forming apparatus, and an image forming process.
Description of Related Art
Electrophotographic photoreceptors (hereinafter, also simply referred to as “photoreceptors”) for image forming apparatuses, such as electrophotographic copiers and printers, should have long service lives and form images with stable quality. The service life of a photoreceptor varies depending on the wear of the surface of the photoreceptor. In addition, fine scratches and uneven abrasion due to the wear cause a reduction in image quality.
A recently developed photoreceptor having high wear resistance, scratch resistance, and environmental stability and a prolonged service life includes a photosensitive layer deposited on an electroconductive support and a surface protective layer of a cured resin on the photosensitive layer.
In such a photoreceptor, in order to improve the wear resistance and the stability of image quality, such as high memory resistance, for example, a surface protective layer further containing high-strength microparticles having hole transportability, p-type semiconductor microparticles, has been proposed (for example, see Japanese Patent Laid-Open Nos. 2013-130603 and 2014-021133).
Even in the photoreceptor having the surface protective layer containing p-type semiconductor microparticles, however, repeated use for a long time causes a problem of occurrence of transfer memory.
For solving the problem of transfer memory, an increase in the content of the p-type semiconductor microparticles may be effective. The increase in the content of the p-type semiconductor microparticles, however, causes another problem, easy fogging. This is probably due to the low surface electrical resistance, i.e., the low potential-holding ability, of the p-type semiconductor microparticles themselves.